mirror of
https://github.com/notwa/mm
synced 2024-05-18 13:23:23 -07:00
Connor Olding
43ce5f0d7e
on my machine; * n64_fast.crc is 29 times faster * Yaz0_fast.decode is 226 times faster
59 lines
1.3 KiB
Cython
59 lines
1.3 KiB
Cython
# decoder ripped from: http://www.amnoid.de/gc/yaz0.txt
|
|
|
|
ctypedef unsigned long ulong
|
|
ctypedef unsigned char uchar
|
|
|
|
cdef ulong get_size(uchar *comp):
|
|
return comp[4]*0x1000000 + comp[5]*0x10000 + comp[6]*0x100 + comp[7]
|
|
|
|
cdef void _decode(uchar *comp, uchar *uncomp):
|
|
cdef:
|
|
ulong src = 16 # skip header
|
|
ulong dst = 0
|
|
uchar valid = 0 # bit count
|
|
uchar curr = 0 # code byte
|
|
|
|
ulong size = get_size(comp)
|
|
|
|
uchar byte1, byte2
|
|
ulong dist, copy, i, n
|
|
|
|
while dst < size:
|
|
if not valid:
|
|
curr = comp[src]
|
|
src += 1
|
|
valid = 8
|
|
|
|
if curr & 0x80:
|
|
uncomp[dst] = comp[src]
|
|
dst += 1
|
|
src += 1
|
|
else:
|
|
byte1 = comp[src]
|
|
byte2 = comp[src + 1]
|
|
src += 2
|
|
|
|
dist = ((byte1 & 0xF) << 8) | byte2
|
|
copy = dst - (dist + 1)
|
|
|
|
n = byte1 >> 4
|
|
if n:
|
|
n += 2
|
|
else:
|
|
n = comp[src] + 0x12
|
|
src += 1
|
|
|
|
for i in range(n):
|
|
uncomp[dst] = uncomp[copy]
|
|
copy += 1
|
|
dst += 1
|
|
|
|
curr <<= 1
|
|
valid -= 1
|
|
|
|
def decode(comp):
|
|
size = get_size(comp)
|
|
uncomp = bytearray(size)
|
|
_decode(comp, uncomp)
|
|
return uncomp
|